Display device

ABSTRACT

A display device is provided, including a first flexible substrate, a second flexible substrate, a TFT circuit, and a liquid-crystal layer. The TFT circuit is formed on the first flexible substrate. The liquid-crystal layer is sealed between the first flexible substrate and the second flexible substrate. The first flexible substrate has a first light transmission chromaticity coordinates (x 1,  y 1 ), and the second flexible substrate has a second light transmission chromaticity coordinates (x 2,  y 2 ), wherein x 1 -x 2 ≥0.002 or y 1 -y 2 ≥0.002.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of China Application No.201910949842.4, filed on Oct. 8, 2019, the entirety of which isincorporated by reference herein.

BACKGROUND OF THE INVENTION Field of the Invention

The application relates in general to a display device, and inparticular to a display device that includes a plurality of substrateswith different chromaticity.

Description of the Related Art

A display device is an optoelectronic device that converts an electricsignal into a visible image, and the viewer can view the imageinformation loaded in the electric signal. In recent years, displaydevices have become quite popular.

In the manufacturing process for a display device, a flexible substratecan be used as a display panel. At present, the industry often usespolyimide (PI) with high temperature resistance as the main body of theflexible substrate. However, the PI substrate processed by thehigh-temperature process is likely to cause the light emitted from thedisplay panel to become more yellowish. Therefore, how to provide adisplay device that can solve the above problems has become an importantissue.

BRIEF SUMMARY OF INVENTION

To address the deficiencies of conventional products, an embodiment ofthe disclosure provides a display device, including a first flexiblesubstrate, a second flexible substrate, a thin-film transistor (TFT)circuit, and a liquid-crystal layer. The TFT circuit is formed on thefirst flexible substrate. The liquid-crystal layer is sealed between thefirst flexible substrate and the second flexible substrate. The firstflexible substrate has a first light transmission chromaticitycoordinates (x1, y1), and the second flexible substrate has a secondlight transmission chromaticity coordinates (x2, y2), whereinx1-x2≥0.002 or y1-y2≥0.002.

An embodiment of the disclosure provides a display device, including afirst composite substrate, a second composite substrate, and a displaymedium layer. The first composite substrate includes a first flexiblesubstrate and a circuit layer, wherein the circuit layer is locatedabove the first flexible substrate and having a thin-film transistor(TFT) circuit. The second composite substrate includes a second flexiblesubstrate. The display medium layer is sealed between the first flexiblesubstrate and the second flexible substrate. The first compositesubstrate has a first light transmission chromaticity coordinates (x1,y1), and the second flexible substrate has a second light transmissionchromaticity coordinates (x2, y2), wherein x1-x2≥0.002 or y1-y2≥0.002.

BRIEF DESCRIPTION OF DRAWINGS

The disclosure can be more fully understood by reading the subsequentdetailed description and examples with references made to theaccompanying drawings, wherein:

FIG. 1 is a schematic view of a display device according to the firstembodiment of the present disclosure.

FIG. 2 is a schematic view showing the cross-sectional structure of thedisplay panel in FIG. 1.

FIG. 3A is a schematic view of the first light transmission chromaticitycoordinates and the second light transmission chromaticity coordinatesat CIE 1931 X-Y chromaticity coordinate (or CIE 1931 chromaticity view).

FIG. 3B is a schematic view showing an original point O set by moving0.002 units along the −X axis direction and 002 units along the −Y axisdirection from the first light transmission chromaticity coordinates(x1, y1).

FIG. 4A is a schematic view showing a variation of the first flexiblesubstrate in the first embodiment.

FIG. 4B is a schematic view showing that the first flexible substrateand the second flexible substrate are doped with elements in differentconcentrations.

FIG. 4C is a schematic view showing that the first flexible substrateand the second flexible substrate are doped with molecular polymers indifferent concentrations.

FIG. 5 shows a schematic view showing that the first flexible substrateundergoes a first processing temperature and the second flexiblesubstrate undergoes a second processing temperature.

FIG. 6 is a schematic view of a display device according to the secondembodiment of the present disclosure.

FIG. 7 is a schematic view of a display device according to the thirdembodiment of the present disclosure.

FIG. 8 is a schematic view of a display device according to the fourthembodiment of the present disclosure.

FIG. 9 is a schematic view of a display device according to the fifthembodiment of the present disclosure.

DETAILED DESCRIPTION OF INVENTION

In the following detailed description, for the purposes of explanation,numerous specific details and embodiments are set forth in order toprovide a thorough understanding of the present disclosure. The specificelements and configurations described in the following detaileddescription are set forth in order to clearly describe the presentdisclosure. It will be apparent, however, that the exemplary embodimentsset forth herein are used merely for the purpose of illustration, andthe inventive concept may be embodied in various forms without beinglimited to those exemplary embodiments. In addition, the drawings ofdifferent embodiments may use like and/or corresponding numerals todenote like and/or corresponding elements in order to clearly describethe present disclosure. However, the use of like and/or correspondingnumerals in the drawings of different embodiments does not suggest anycorrelation between different embodiments. The directional terms, suchas “up”, “down”, “left”, “right”, “front” or “rear”, are referencedirections for accompanying drawings. Therefore, using the directionalterms is for description instead of limiting the disclosure.

It should be understood that elements specifically described orillustrated may exist in various forms well known to those skilled inthe art. In addition, when a layer is “on” another layer or substrate,it may mean “directly” on the other layer or substrate, or it may meanthat another layer is interposed between the certain layer and the otherlayer or substrate.

In this specification, expressions to show the relativity are used. Forexample, “lower”, “bottom”, “higher” or “top” are used to describe theposition of one element relative to another. It should be appreciatedthat if a device is flipped upside down, an element at a “lower” sidewill become an element at a “higher” side.

The terms “about” and “substantially” typically mean a value is in arange of +/−20% of a stated value, more typically +/−10% of the statedvalue and even more typically +/−5% of the stated value. The statedvalue of the present disclosure is an approximate value. When there isno specific description, the stated value includes the meaning of“about” or “substantially”.

It should be noted that although in the present disclosure it uses aliquid-crystal display as an example, the type of the display devices isnot limited thereto. The display device in this disclosure may include,for example, a liquid-crystal display (LCD), a light-emitting diode(LED) display, or a display using other suitable display medium. Thelight-emitting diode may include, for example, an organic light-emittingdiode (OLED), a sub-millimeter light-emitting diode (mini LED), a microlight-emitting diode (micro LED), or a quantum dot light-emitting diode(quantum dot LED, QLED/QDLED). The display device disclosed in thisdisclosure may also be a tiled display device formed by splicingmultiple display panels, but it is not limited thereto.

First Embodiment

Referring to FIGS. 1 and 2, FIG. 1 is a schematic view showing a displaydevice 100 according to the first embodiment of the present disclosure,and FIG. 2 is a schematic view showing a cross-sectional structure ofthe display panel 101 in FIG. 1. In this embodiment, the display device100 may be a display device for displaying a picture. The display device100 includes a display panel 101 and a backlight module BL. The displaypanel 101 is disposed opposite the backlight module BL.

The display panel 101 may include a first flexible substrate 102, asecond flexible substrate 104, a thin film transistor circuit 106, and adisplay medium layer 108. The second flexible substrate 104 is disposedon the first flexible substrate 102, and the thin film transistorcircuit 106 and the display medium layer 108 are disposed between thefirst flexible substrate 102 and the second flexible substrate 104. Thethin film transistor circuit 106 is disposed between the first flexiblesubstrate 102 and the display medium layer 108. The display medium layer108 may be a liquid-crystal layer, but is not limited thereto. In someembodiments, the first flexible substrate 102 or the second flexiblesubstrate 104 may be a touch substrate. It should be noted that, in thisdisclosure, the display medium is changed according to the type of thedisplay device. For example, when the display device is a liquid-crystaldisplay, the display medium may be a liquid crystal, and in an organiclight-emitting diode display, the display medium may be an organiclight-emitting diode (OLED). Display mediums of other types of displaysare so forth.

In this embodiment, a color filter 110 can be selectively disposedbetween the first flexible substrate 102 and the second flexiblesubstrate 104, but the disclosure is not limited thereto. Theaforementioned color filter 110 may have filter portions such as a redfilter portion 110R, a green filter portion 110G, and a blue color 110B.In other embodiments, the color filter 110 may also include filterportions of other colors (such as yellow), or include materials withlight conversion characteristics (such as quantum dot materials,fluorescent materials, phosphorescent materials, or combinationsthereof), but not limit thereto.

In this embodiment, the first flexible substrate 102 may have a firstlight transmission chromaticity coordinates (x1, y1) on the CIE 1931 xychromaticity coordinates, and the second flexible substrate 104 is inthe CIE 1931 and may have a second light transmission chromaticitycoordinates (x2, y2), as shown in FIG. 3A. For example, a film colorpoint measurement method can be used to measure the light transmissionchromaticity coordinates of the aforementioned substrate: thismeasurement method uses a reference light source to illuminate asubstrate to be measured, and the reference light emitted by thereference light source has a first spectral intensity distribution inwhich there is respectively a light intensity value at every wavelengthvalue. The reference light becomes a penetrating light after penetratingthe substrate to be tested, and the penetrating light has a secondspectral intensity distribution in which there is respectively anotherlight intensity value at every wavelength value. And divide the secondspectral intensity distribution of the transmitted light by the firstspectral intensity distribution of the reference light (that is, startfrom the shortest wavelength, and gradually calculate the intensityratio of the penetrating light and the reference light at the samewavelength value until the longest wavelength), then a third spectralintensity distribution can be obtained. Finally, according to the thirdspectral intensity distribution, the light transmission chromaticitycoordinate value of the penetrating light is calculated.

As shown in FIG. 3A, in an embodiment, the second light transmissionchromaticity coordinates (x2, y2) are located at a lower left locationof the first light transmission chromaticity coordinates (x1, y1), whichmeans that in this embodiment, the second flexible substrate 104 is morebluish than the first flexible substrate 102. The difference inchromaticity between the two substrates can be obtained due to theprocess difference experienced by the first flexible substrate 102 andthe second flexible substrate 104 or obtained by other methods. The wayto make the chromaticity difference will be detailed later.

In this way, when the backlight module BL illuminates the display panel101, since there is a chromaticity difference between the first flexiblesubstrate 102 and the second flexible substrate 104, the light color ofthe display panel 101 is compensated. That is, the chromaticitycoordinates of the light color of the display panel 101 are locatedbetween the first light transmission chromaticity coordinates and thesecond light transmission chromaticity coordinates. In the presentdisclosure, by compensating for the light color of the display panel101, the phenomenon that the light color of the display device 100 withoriginally used PI is more yellowish can be improved.

In the embodiment of the present disclosure, the difference between thefirst light transmission chromaticity coordinates (x1, y1) and thesecond light transmission chromaticity coordinates (x2, y2) can be seenin FIG. 3B. Starting from the first light transmission chromaticitycoordinates (x1, y1), and moving 0.002 units along the −X axis and 002units along the −Y axis, the origin point O is set, i.e. thechromaticity coordinates origin O are (x1—0.002, y1—0.002), and fourquadrants are defined. As shown in FIG. 3B, when the first lighttransmission chromaticity coordinates (x1, y1) are in the first quadrantand the second light transmission chromaticity coordinates (x2, y2) arein the third quadrant, we may get x1-x2>0.002 and y1−y2>0.002.

In some embodiments, the second light transmission chromaticitycoordinates of the second flexible substrate 104 may fall within thesecond quadrant, the fourth quadrant, or the origin point O. That is,x1-x2≥0.002 or y1-y2≥0.002, or x1-x2≥0.002 and y1-y2≥0.002. In this way,the color of the light emitted from the display device 100 can becompensated. In some embodiments, x1-x2≥0.005 or y1-y2≥0.005. In otherembodiments, 0.002≤x1-x2≤0.030 or 0.002≤y1-y2≤0.030.

The following provides various ways to adjust the first lighttransmission chromaticity coordinates (x1, y1) or the second lighttransmission chromaticity coordinates (x2, y2).

FIG. 4A shows a variation of the first flexible substrate 102. As shownin FIG. 4A, the thickness w1 of the first flexible substrate 102 isthicker than the thickness w2 of the second flexible substrate 104. Forexample, in some embodiments, the thickness w1 of the first flexiblesubstrate 102 is 10% to 100% thicker than that of the second flexiblesubstrate 104. In this embodiment, the second flexible substrate 104 mayhas a thickness of about 10 μm, but it is not limited to this. When adifference in chromaticity already exists between the first flexiblesubstrate 102 and the second flexible substrate 104 (that is, the firstflexible substrate 102 of the same thickness is relatively yellowish),increasing the thickness of the flexible substrate 102 will make it moreyellowish in the CIE 1931 xy chromaticity coordinates (i.e., the firstlight transmission chromaticity coordinates (x1, y1) moves to the upperright)to achieve the condition: x1-x2≥0.002 or y1-y2≥0.002, orx1-x2≥0.002 and y1-y2≥0.002.

FIG. 4B is a schematic view showing that the first flexible substrate102 and the second flexible substrate 104 are doped with differentconcentrations of the elements. The first flexible substrate 102includes a first polymer layer 1022, and the second flexible substrate104 includes a second polymer layer 1042. The first polymer layer 1022and the second polymer layer 1042 may respectively include a firstatomic concentration and a second atomic concentration of at least oneelement of Si, F, Ge, and C, wherein the first atomic concentration isgreater than the second atom concentration. Since the elements of Si, F,Ge, and C will increase the transition energy, this means that when theconcentration of at least one of the above elements in the flexiblesubstrate is high, the wavelength of the light which passes through thesubstrate will become longer, and the overall substrate will be moreyellowish; on the contrary, if the concentration of at least one of theabove elements becomes low, the wavelength of light passing through thesubstrate will become shorter, and the overall substrate is more bluish.In this way, the first flexible substrate 102 and the second flexiblesubstrate 104 can have a chromaticity difference. In this embodiment,the element concentration may be adjusted in the above manner, and thedifference between the first light transmission chromaticity coordinates(x1, y1) and the second light transmission chromaticity coordinates (x2,y2) may be in the condition: x1-x2≥0.002 or y1-y2≥0.002, or x1-x2≥0.002and y1-y2≥0.002. In another embodiment, 0.002≤x1-x2≤0.030 and/or0.002≤y1-y2≤0.030. It should be noted that the addition of elements suchas Si, F, Ge, and C to the flexible substrate can adjust the lighttransmission chromaticity coordinates of the substrate. Therefore, whena flexible substrate (such as the first flexible substrate 102) isexcessively yellowed due to processing temperature or other factors, byadjusting the difference in atomic concentration between the substrate(such as the first flexible substrate 102) and another substrate (suchas the second flexible substrate 104), for example, the first atomicconcentration in the first flexible substrate 102 is less than thesecond atomic concentration in the second flexible substrate 104, thedifference between the first light transmission chromaticity coordinates(x1, y1) of the first flexible substrate 102 and the second lighttransmission chromaticity coordinates (x2, y2) of the second flexiblesubstrate 104 may fall within an appropriate range, for example,0.002≤x1-x2≤0.030 and/or 0.002≤y1-y2≤0.030.

FIG. 4C shows a schematic view showing the aforementioned first polymerlayer 1022 and second polymer layer 1042 are doped with differentconcentrations (or numbers) of conjugated double bond polymers. In someembodiments, the conjugated double bond polymer contained in the firstpolymer layer has a first concentration, the conjugated double bondpolymer contained in the second polymer layer has a secondconcentration, and the first concentration is different from the secondconcentration. Similar to the method of adjusting the wavelength oflight by adjusting the element concentration of at least one of Si, F,Ge, and C in the embodiment of FIG. 4B, in this embodiment, a higherconcentration of a polymer containing conjugated double bonds is added,for example, the benzene ring, can also make the substrate moreyellowish. The above manner causes a chromaticity difference between thefirst flexible substrate 102 and the second flexible substrate 104. Inanother embodiment, the concentrations of the triple bond polymer of thefirst flexible substrate 102 and the second flexible substrate 104, suchas benzonitrile (C₆H₅CN), may be adjusted, and a chromaticity differenceis between the first flexible substrate 102 and the second flexiblesubstrate 104. That is, the conjugated triple bond polymer contained inthe first polymer layer has a first concentration different from thesecond concentration of the conjugated triple bond polymer contained inthe second polymer layer. The concentration of aforementioned elementsor molecules in the substrate can measured by observing thecharacteristics of absorption or transition energy with a materialanalyzer, such as Fourier transform infrared spectrometer (FTIR), X-rayphotoelectron spectrometer (XPS), near-edge X-ray analysis (NEXR), etc.

FIG. 5 shows that the first flexible substrate 102 may undergo a processwith a first processing temperature of T1, and the second flexiblesubstrate 104 may undergo a process with a second processing temperatureof T2. Since the general flexible substrate contains polyimide (PI)material, the higher the temperature of the process which the polyimideundergoes, the more yellowish the color of the substrate afterprocessing is measured (that is, the light transmission chromaticitycoordinates of the light through the substrate is more yellowish).Therefore, due to the difference between the first processingtemperature T1 and the second processing temperature T2, thechromaticity of the first flexible substrate 102 and the second flexiblesubstrate 104 may be different. In this embodiment, the first processingtemperature T1 is greater than the second processing temperature T2.

It should be noted that the above-mentioned methods of adjusting thesubstrate thickness (FIG. 4A), doping with different concentrations ofspecific elements (FIG. 4B), doping with different proportions of doubleor triple bond polymers (FIG. 4C), and undergoing different processingtemperatures (FIG. 5) can be combined with each other, and thedifference between the first light transmission chromaticity coordinates(x1, y1) and the second light transmission chromaticity coordinates (x2,y2) is: x1-x2≥0.002 or y1-y2≥0.002, or x1-x2≥0.002 and y1-y2≥0.002. Inanother embodiment, 0.002≤x1-x2≤0.030 and/or 0.002≤y1-y2≤0.030.

Second Embodiment

Please refer to FIG. 6, which is a schematic view of a display device100A according to a second embodiment of the present disclosure (wherethe backlight module BL is omitted). Compared to the foregoing firstembodiment (FIG. 2), the first flexible substrate 202 and the secondflexible substrate 204 of the display panel 201 in the display device100A include a multi-layer structure respectively. The first flexiblesubstrate 202 includes a first layer 2022, a second layer 2024 and athird layer 2026. The second flexible substrate 204 includes a fourthlayer 2042 and a fifth layer 2044, but the number of layers included inthe first flexible substrate 202 and the second flexible substrate 202is not limited to this. In the aforementioned five layers (the firstlayer 2022 to the fifth layer 2044), two of the layers need to beflexible substrate layers, the other three layers can be selected to bespecific functional layers according to actual needs , such as diffuserfilm(s) to increase viewing angle, brightness enhancement film(s) toincrease brightness, optical film(s), protective layer(s), stressbalance layer(s), planarization layer(s), buffer layer(s), or otherlayers with specific functions. In addition, it should also be notedthat the type and/or stacking order of each layer in this embodiment canbe adjusted according to actual needs. For example, in an embodiment,the display panel 201 includes: the first layer 2022 as a first flexiblesubstrate layer, the second layer 2024 as a stress balance layer, thethird layer 2026 as a planarization layer, and the fourth layer 2042 asa protective layer, and the fifth layer 2044 as a second flexiblesubstrate layer. In another embodiment, the display panel 201 includes:the first layer 2022 as a stress balance layer, the second layer 2024 asa first flexible substrate layer, the third layer 2026 as a bufferlayer, the fourth layer 2042 as a second flexible substrate layer, andthe fifth layer 2044 as a stress balance layer. That is to say, in someembodiments, the flexible substrate layer may be located between twoother layers, or the flexible substrate layer may be located between thedisplay medium layer 108 and other layers.

As shown by FIG. 6, the first flexible substrate 202 includes threelayers (layers 2022, 2024, and 2026), and the second flexible substrate204 includes two layers (layers 2042, 2044). Since each layer may haveits own different refractive index, it will interfere with differentwavelengths. The overall chromaticity of the first flexible substrate202 and the second flexible substrate 204 may change independently,resulting in a chromaticity difference, for example, x1-x2≥0.002 and/ory1-y2≥0.002. In another embodiment, 0.002≤x1-x2≤0.030 and/or0.002≤y1-y2≤0.030.

Third Embodiment

Please refer to FIG. 7, which is a schematic view of a display device100B according to a third embodiment of the present disclosure (wherethe backlight module BL is omitted). Compared with the second embodiment(FIG. 6), other layers are added between the first flexible substrate202 and the display medium layer 108, and between the second flexiblesubstrate 204 and the display medium layer 108 in this embodiment. Forexample, a circuit layer 306 is provided on the first flexible substrate202 of the display panel 301 in the display device 100B, wherein thecircuit layer 306 includes a thin-film transistor (TFT) circuit 106, aninsulating layer 3300, an electrode layer 3350 and a first alignmentlayer 3400. A color filter layer 3700, an overcoat layer 3800, and asecond alignment layer 3900 are also included between the secondflexible substrate 204 and the display medium layer 108, and aprotective layer 3600 is located above the fifth layer 2044. It shouldbe noted that, in this embodiment, the layers adjacent to the firstflexible substrate 202 or the second flexible substrate 204 are notlimited to the layers shown in FIG. 7.

The aforementioned first flexible substrate 202 and the circuit layer306 (but not limited to) may be comprised in a first composite substrate40. By the aforementioned film color point measurement method, apenetrating light (the light emitted by the reference light source andpenetrating the first composite substrate 40) is measured to obtain afirst light transmission chromaticity coordinates (x1, y1). The secondflexible substrate 204 and other adjacent layers can be comprised in asecond composite substrate 50. By measuring the penetrating light (thelight emitted by the reference light source and penetrating the secondcomposite substrate 50), the second light transmission chromaticitycoordinates (x2, y2) is obtained.

Based on the foregoing embodiments, the chromaticity difference range ofthe first composite substrate 40 and the second composite substrate 50may be x1-x2≥0.002 and/or y1-y2≥0.002. In another embodiment,0.002≤x1-x2≤0.030 and/or 0.002≤y1-y2≤0.030. It should be noted that whenmeasuring the light transmission chromaticity coordinates, themeasurement point needs to be carefully selected and the light emittedby the reference light source does not pass through the color filters,metal, black matrix and any other parts with opaque materials in thecomposite substrate, and not to affect the finally measured lighttransmission chromaticity coordinates.

Fourth Embodiment

Please refer to FIG. 8, which is a schematic view of a display device100C according to a fourth embodiment of the present disclosure (wherethe backlight module BL is omitted). As shown in FIG. 8, by adjustingthe opening ratio of the sub-pixels corresponding to the regions of thered filter 410R, the green filter 410G, and the blue filter 410B in thedisplay panel 401, the light chromaticity of the display panel 401 canbe further adjusted. For example, in this embodiment, in the displaypanel 401 of the display device 100C, the sub-pixel opening ratiocorresponding to the blue filter portion 410B is higher (in FIG. 8, itis represented by the area of the blue filter portion 410B being greaterthan the red filter portion 410R and the green filter portion 410G), andthe chromaticity of the light emitted from the display panel 401changes, for example, it is more bluish.

Fifth Embodiment

Please refer to FIG. 9, which is a schematic view of a display device100D according to a fifth embodiment of the present disclosure. Comparedwith the first embodiment (FIGS. 1-2), this embodiment has a backlightmodule BL′ which emits light that is more bluish than the backlightmodule BL in the First Embodiment. That is, it is closer to the standardorigin (0,0) of the CIE 1931 xy chromaticity coordinate than the firstlight transmission chromaticity coordinate (x1, y1). In this way, thelight chromaticity of the overall display device 100D can be morebluish.

It should be noted that the method of changing the opening ratio of thesub-pixels in the fourth embodiment and the method of changing the lightchromaticity of the backlight module in the fifth embodiment can be usedindependently or combined with other embodiments, to compensate for thelight chromaticity of the display device.

In summary, the present disclosure provides a display device, includinga first flexible substrate, a second flexible substrate, a TFT circuit,and a liquid-crystal layer. The TFT circuit is formed on the firstflexible substrate. The liquid-crystal layer is sealed between the firstflexible substrate and the second flexible substrate. The first flexiblesubstrate has a first light transmission chromaticity coordinates (x1,y1), and the second flexible substrate has a second light transmissionchromaticity coordinates (x2, y2), wherein x1-x2≥0.002 or y1-y2≥0.002.

The embodiment of the present disclosure has at least one of thefollowing advantages or effects. Through the chromaticity differencebetween the first flexible substrate and the second flexible substratein the CIE 1931 xy chromaticity coordinate, ((x1, y1) and (x2, y2),wherein x1-x2≥0.002 or y1-y2≥0.002), the light chromaticity of thedisplay device can be compensated, and the chromaticity of the light canbe adjusted. In addition, by adjusting the opening ratio of a sub-pixel,such as the sub-pixel corresponding to a specific color in the colorfilter having a higher opening ratio, or adjusting the chromaticity ofthe light emitted by the backlight module, the light chromaticity of thedisplay device can also be adjusted.

Use of ordinal terms such as “first”, “second”, “third”, etc., in theclaims to modify a claim element does not by itself connote anypriority, precedence, or order of one claim element over another or thetemporal order in which acts of a method are performed, but are usedmerely as labels to distinguish one claim element having a certain namefrom another element having the same name (but for use of the ordinalterm) to distinguish the claim elements.

It will be apparent to those skilled in the art that variousmodifications, combinations and variations can be made in thedisclosure. It is intended that the standard and examples be consideredas exemplary only, with the true scope of the disclosed embodimentsbeing indicated by the following claims and their equivalents.

What is claimed is:
 1. A display device comprising: a first flexiblesubstrate; a second flexible substrate; a TFT circuit formed on thefirst flexible substrate; and a liquid crystal layer sealed between thefirst flexible substrate and the second flexible substrate, wherein thefirst flexible substrate has a first light transmission chromaticitycoordinates (x1, y1), the second flexible substrate has a second lighttransmission chromaticity coordinates (x2, y2), and wherein x1-x2≥0.002or y1-y2≥0.002.
 2. The display device according to claim 1, wherein thex1-x2≥0.002 and y1-y2≥0.002.
 3. The display device according to claim 1,wherein the x1-x2≥0.005 or y1-y2≥0.005.
 4. The display device accordingto claim 3, wherein the x1-x2≥0.005 and y1-y2≥0.005.
 5. The displaydevice according to claim 1, wherein the x1-x2≤0.030 or y1-y2≤0.030. 6.The display device according to claim 1, wherein the first flexiblesubstrate comprises a first polymer layer which has a first atomicconcentration of an element selected from a group consisting of Si, X1,and X2, the second flexible substrate comprises a second polymer layerwhich has a second atomic concentration of the element, and the firstatomic concentration is greater than the second atomic concentration. 7.The display device according to claim 1, wherein the first flexiblesubstrate comprises a first polymer layer which has a first atomicconcentration of an element selected from a group consisting of F, Y1,and Y2, the second flexible substrate comprises a second polymer layerwhich has a second atomic concentration of the element, and the firstatomic concentration is smaller than the second atomic concentration.